Net Loss Per Ordinary Share - Computation of Basic and Diluted Loss Per Ordinary Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
Numerator:
Net loss	$ (10,818)	$ (15,463)
Denominator:
Weighted-average ordinary shares - basic	35,940,304	34,080,330
Weighted-average ordinary shares - diluted	35,940,304	34,080,330
Net loss per ordinary share:
Basic	$ (0.30)	$ (0.45)
Diluted	$ (0.30)	$ (0.45)